Screenshot from Familiars, a game by Nigel Nelson

Familiars.io is a minimalist monster-catching game that went online last year, and right now, you can play it inside Twitter. As developer Nigel Nelson tweeted this afternoon, he ported (or in his words, “smuggled”) the entire game to an embedded Twitter card. That means that you can play it directly through Twitter’s web interface or mobile app.

The game is built around Pokémon-style exploration and combat in a shared, lo-fi setting. You can wander around capturing enemies to expand your team of familiars, then use them to fight other players (or simply walk around saying “howdy,” if you prefer.)

“Me and my brother used to do this thing where we would start new games on Pokémon Red and Blue, progress through the game as fast as we could in a 3-hour period, and then fight each other with our pokémon teams,” Nelson says. “A year ago I was looking for a new project, and my brother suggested that a multiplayer Pokémon-like PVP experience might be fun, and I thought it was a great idea.”

The game’s Twitter version won’t necessarily be online for long. Familiars.io is using the Player Cards that Twitter offers for linear media, and Twitter admonishes users to not “circumvent the intended use of the Card” with interactive experiences. In 2015, Twitter disabled embedding classic MS-DOS games in tweets. But the game has nonetheless taken off on the platform. Nelson tells The Verge that he’s seen about 3,000 logins and 250 players online at a time, compared to a standard user base of one or two people. “I’ve had a few ideas for new fun things to add, but I think I might need to take a step back to figure out how to make my servers accommodate the increased player base,” he says.

Familiars.io is a hobby and a work in progress; some users have tweeted reports of bugs, particularly on Firefox. But I’ve enjoyed the illicit thrill of Twitter gaming on desktop Chrome and Android’s Twitter app just fine — and Familiars.io itself isn’t going anywhere. If the game gets taken off Twitter, its virtual world is still available on the web.